It Wasn't Just Neanderthals: Ancient Humans Had Sex with Other Hominids

Scientists have collected evidence for years that modern humans interbred with our ridge-browed Neanderthal ancestors in Eurasia. But in Africa, where the homo sapien species is said to have emerged, a lack of genetic evidence has left researchers scratching their heads about exactly how we came to beat out not only the Neanderthals, or homo neanderthalis, but other archaic species like homo erectus and homo habilus. A new paper published by Michael Hammer from the University of Arizona, however, provides evidence that homo sapiens not only interbred with Neanderthals in Eurasia, they also had sex with several species of our ancestors across the African continent. And they did it often. "We think there were probably thousands of interbreeding events," said Hammer. "It happened relatively extensively and regularly."

What we know about the history of our species has long been determined by what we can learn from our ancestors' remains. As recently as five years ago, researchers deduced that humans and Neanderthals had interbred at some point based on the shapes of skulls found in caves or buried under thousands of years worth of soil. A ground-breaking paper published last year by Swedish evolutionary biologist Svante Pääbo in Science brought genetics into the equation. Pääbo provided genetic proof that homo sapiens migrated out of Africa and into the Neanderthal-occupied Eurasian continent, where they met and mated with the more primitive men. Pääbo and his team made the discovery while comparing samples of Neanderthal DNA with that of modern human DNA....